Camera views of all home access points.

Solid-core wood or metal-clad doors with non-removable hinges.

Security film on all accessible windows.

That's just a sampling of the multiple security upgrades the US Capitol Police are recommending for one senator — Republican Mike Crapo — at his homes in Washington, DC, and Idaho Falls, Idaho, according to a recent letter from his campaign lawyers to federal regulators.

"Current events involving concrete threats of physical violence against Members and their families have prompted Members to consider further security measures for themselves and their families," the lawyers wrote. "As has been well-documented in the media, Members and their families continue to endure threats and security breaches…"

The November 18 letter from Crapo's campaign committee lawyers to the Federal Election Commission provides a glimpse of the heightened security measures Capitol Police believe are warranted for one member in the current environment.

The letter underscores how serving in Congress may require living in a fortress as threats of violence against members surge in recent years — the January 6, 2021, attack on the US Capitol the most notable of a series of violent incidents.

The October attack on House Speaker Nancy Pelosi's husband, Paul Pelosi, with a hammer at their San Francisco home is a stark reminder of the dangers both members and their families face.

For Crapo's homes, Capitol Police recommend not just an alarm system, but one with video door intercom stations, motion sensors, duress alarms and mobile alarm pendants, according to Crapo's lawyers. 

The ideal exterior closed-circuit video system, meanwhile, would provide live monitoring, video recording, and motion and sound detection. And security film on all accessible windows would prevent "surreptitious observation into the residence," they wrote, citing Capitol Police recommendations.

Spokespeople for Crapo and Capitol Police did not immediately respond to a request to comment.

Crapo's lawyers wrote to the FEC because they want to know how to best pay for all of these updates on two homes. They're seeking confirmation that a senator can use campaign funds, under the Federal Election Campaign Act, to cover residential security expenses.

The FEC previously advised lawmakers that certain safety expenditures expenditures aren't considered a personal use of campaign funds — something that's generally illegal — and the commission has in other instances approved similar security upgrades on a case-by-case basis.

But the FEC cautioned in a 2017 advisory that their conclusion may not apply if threats diminish, they noted. Crapo's lawyers wrote, however, that the threat environment since then "has actually worsened."

"The collective threat faced by Members of Congress warrants increased security measures even when an individual Member has not yet received direct threats," they wrote.

Crapo's letter points to multiple examples of threats and violence against members, including the mass shootings that severely injured House Republican Whip Steve Scalise of Louisiana in 2017 and former Rep. Gabrielle Giffords, an Arizona Democrat, in 2011. Six people were killed in the attack on Giffords.

A neighbor assaulted Sen. Rand Paul of Kentucky in 2017, and earlier this year, a man attacked Rep. Lee Zeldin, a Republican from New York who was running for governor, during a campaign event. Zeldin escaped injury.

Capitol Police surveys of Crapo's homes indicated that members of Congress "'may become the target of potential acts of terrorism, civil disobedience, civil disturbance, threats of violence, theft of services, theft of physical or intellectual property, burglary, vandalism, other acts of criminal mischief, and unauthorized trespassing,'" the lawyers wrote, quoting the surveys.

Crapo, who won reelection to his 5th term last month, is the top-ranking Republican on the Senate Finance Committee. In May, he joined other Republican senators in announcing a bill designed to protect government employees and their families from having their home addresses listed publicly online after activists organized protests at conservative Supreme Court justices' homes.

"Public servants and their families should not be subjected to protests or acts of violence at their private homes," Crapo said in a statement at the time.